One of the driving forces behind the proliferation of commercial Unmanned Aerial Vehicles (UAVs) is their applications in agriculture. In particular, obtaining frequent aerial images of their farms allow the farmers to make informed decisions related to fertilizer application, irrigation, pesticide application and other farm practices. In a typical application, a UAV equipped with (often multi-spectral) cameras is flown over the field. The images are geo-tagged and a mosaic is built to inform farm decisions.